It is frequently desired when mounting a picture or the like in a frame to provide a mat around the picture between the picture and the frame. Alternatively, a mat can be used as a picture frame. In either case, it is necessary to provide an opening in the mat through the picture can be seen. This is frequently done by hand and is a time consuming and somewhat imprecise method.
Automatic mat cutters have been provided in the prior art which use a die to cut a rectangular opening in a mat. However, the edges of the die cut mat must necessarily be at 90.degree. to the mat whereas it is usually desired to provide a bevel, usually 45.degree., cut in the opening away from the picture to further enhance the appearance of the mat.
In order to cut a 45.degree. angle automatically, prior art devices have been disclosed which could cut a straight beveled cut in a mat. However, except for a square opening, the length of cut had to be continually adjusted or a plurality of machines used to produce a large number of mats in a reasonable period of time.
A number of manually operated mat cutters have also been disclosed in the prior art. Typically, these mat cutters include a guide beneath which the mat to be cut is precisely located. A cutting blade is then mounted for reciprocation along the guide to cut the mat at the desired location. Stops are provided along the guides to precisely limit the length of cut. Devices of this type are disclosed in U.S. Pat. No. 4,038,751 (Albright), No. 3,463,041 (Shapiro et al), and No. 3,527,131 (Ellerin et al).